Flat Roof Systems

VaHouse · 11-21-2007, 08:25 PM

I'm looking for advice on Flat Roof systems. I have a closed-in porch off of the side of my house with a flat roof. I'm thinking of using the roof as a deck, b/c it's right off of the master bedroom. The old roof is pretty much shot and I'm looking for a long-lasting option that would keep water out of the main floor and allow me to walk on the roof on a regular basis. I've talked to a couple of roofers and I've been recommended three possible options so far: (i) EPDM heat welded system, (ii) TPO heat welded system and (iii) Duradek's outdoor flooring system. I'm leaning toward the last option based on what I have read so far, but I feel I'm over my head on this one. There seem to be dozens of different choices. Any thoughts?

Oh, I suppose I should mention that this isn't really a "DIY" project; I plan on hiring a professional. So, I don't need advice on how to install any of the options, just on which one to order.

Thanks.

tinner666 · 11-21-2007, 09:11 PM

Personally, I prefer the 060 EPDM. I think the fiberboard would be better than ISO, but it's just my opinion. TPO seems 'brittle' to me. Not familiar with Duradek. And I'm a 'sloped roof' roofer, so I only do a few flats a year and I DON'T consider myself any authority on flat roofs.

**Ed the Roofer** · 11-21-2007, 09:56 PM

I feel a double layer of APP modified bitumen would be the most durable and least likely to get leaks from usage and possible cigarrette ash holes.

(Did I just say, Ash-Holes?)

TRG, I believe will offer some support for your Dura Deck stuff. I don't know too much about that.

Ed

the roofing god · 12-03-2007, 03:50 AM

I would follow what ed said,usually we would set strips of smooth bitumen under where we would put sleepers for attaching a regular deck to,I would recommend doing it with screws in a sectional design(like parquet),in case there ever is a problem sections could be removed to fix any problems then put back easily-I`ve heard good things about the dens deck but have never personally used it

Richmond Roofer · 12-07-2007, 04:12 PM

VA House -

I think the question is do you want a roof or a roof/deck. If you simply want a roof - EPDM, TPO or Modified Bitumen (APP or SBS) are all acceptable options. APP and SBS Membranes are not well suited for dead level roof deck -- so put some slope in the deck.

If you want a roof/deck - you should consider what you are getting with the duradek product. It is a high quality vinyl membrane "roofing" that covers the deck and keeps the surface below it dry. Duradeck is not typically installed over living/conditioned spaces. It's function is more to protect a potential outdoor space from water above - ie. a second floor deck with duradeck over a screened in porch. So if you are not trying to make the old porch a bedroom or other conditioned, livable spece, I think the duradek is a fine product. (Side note: Duradek is a proprietary product - so any future repairs or modifications to it must be done by a licensed installer)

If you have a conditioned space then you need both a roof and a deck. EPDM, TPO and Mod Bit aree all fine choices. I personally lean towards EPDM. The roofing should be installed over a solid substrate.

The devil is in the details and the roof needs to be installed and then have the sleepers flashed into the roof and the deck installed over the sleepers with a protective membrane or seperator between the deck and the sleeper. If the sleepers are installed over an insulation with low compressive strength - ie wood fiber or polyiso - the deck will crush the insulation and pinch the roof membrane and you will have a leak (eventually).

I do not know what you have based on your posting - but those are some things to consider. Good Luck.

Scott

modusvivendi · 08-06-2012, 12:32 PM

I have a question for you Richmond Roofer. Can you tell me if I can have a roof top deck WITHOUT sleepers etc over a "conditioned" room if I use pvc as the roof membrane? A lot of posts here seem to suggest it can be done.thanks